The objective of this study is to determine the prevalence of β-haemolytic streptococci in the pharynx and antibodies to β-haemolytic streptococci in school children 5–15 years of age in the tri-island state of Grenada. Blood samples and throat swabs were obtained from 1388 school children, aged 5–15 years old attending randomly selected schools in each parish of the tri-island state of Grenada. Serum samples were subjected to antistreptolysin O testing (ASOT) while throat swabs were cultured on sheep blood agar plates. The prevalence of positive throat swab was 15.4% (95% CI = 13.4%, 17.2%). The rate was highest in St Patrick (21.8%) and lowest in Carriacou (5.7%). The prevalence of antibodies was 38.6% (95% CI = 37.6%, 42.8%). It was highest in St Patrick (54.4%) and lowest in Petit Martinique (26.8%). In St Patrick, males were significantly more likely than females to have a positive ASOT (p = 0.0084). In St George’s, males were significantly more likely than females to have a positive throat culture (p = 0.0172). Thirty-four per cent of the positive cultures were type A, 10% were type C and 56% type G. The data illustrate that there is a high prevalence of β−haemolytic streptococci in school children in certain parishes in Grenada. Public health measures should address prevention and control of β-haemolytic streptococcal infection in order to prevent the possible sequelae of this disease.